1. Field of the Invention
This invention relates to a composition for rectal administration, more particularly to a composition for rectal administration suitable for local curing such as curing of hemorrhoids or the like, which composition comprises an acrylic acid polymer, a vasoconstrictor and a rectal tissue-curing agent, with which the concentration of the curing agent in the rectal tissue is increased and the potency of the curing agent continues so as to be "long acting."
2. Background Art
It is known that conventional preparations for rectal administration, such as a suppository and the like, when administered to an anorectal region, spread with time from the administered site to the upper region of the rectum because a base in the preparation is melted at the body temperature to become a liquid state. For the purpose of local curing, such as curing of hemorrhoids or the like, the spreading of the preparation to the upper region of the rectum results in a decrease in the amount of the preparation present in the vicinity of the affected region. Therefore, reports have been made on innovations in preparations for rectal administration for the purpose of preventing the spread of the preparation in the rectum and allowing the preparation to remain in the vicinity of the affected region.
For example, JP-A-54-26325 discloses a preparation for rectal administration which remains in the vicinity of the affected region of the rectum and which contains a metal salt of polyacrylic acid. A mixture of polyacrylic acid and polyvinylpyrrolidone for such a purpose is disclosed in JP-A-6-40889 and the use of a carboxyvinyl polymer for such a purpose is disclosed in JP-A-63-280016 and JP-A-1-143825.